A snap hook is a hook which comprises a hook body having a base end which includes a hook eye or other connector for connecting it to a hook line. An elongated shank extends from the hook eye to a bight. The bight is connected to a tine. The hook eye, the shank, the bight and the tine together form a hook opening. The tine end and the hook eye together define a hook throat providing an avenue into and out from the hook opening. A snap finger is pivotally connected to the base end of the hook body and a spring is provided for biasing the snap hook into a hook throat closing position against the tine end. The snap finger is movable away from the tine end, against the spring force, into a hook throat opening position.
It is known to provide a snap hook of this type with a release tether that is used to pull the snap finger into a throat opening position. Examples of prior art snap fingers with a tether release feature, existing in the patent literature, are shown by U.S. Pat. No. 4,193,627, granted Mar. 18, 1980 to Albert W. Cranston and William J. Rowell; U.S. Pat. No. 4,195,872, granted Apr. 1, 1980 to Clifford I. Skaalen and Phillip M. Kling; and U.S. Pat. No. 4,751,892, granted Jun. 21, 1988 to David Sechel, Dennis DeTillio and Alan Szucs. Each of these patents shown a release tether that is connected to the snap finger and extends through an opening or passageway in the hook shank. However, the hooks disclosed by these patents involve a substantially different mode of operation than the snap hooks of the present invention.
It is an object of the present invention to provide a snap hook in which an initial pull on the release tether, accompanied by a release of tension in the hook line, will cause the snap hook to rotate in position to place an eye that is in the hook opening against the inner surface of the hook tine, so that a continuation of the pull on the release tether will first swing the snap finger into a hook throat opening position and then pull the hook away from engagement with the eye. Each of the snap hooks shown by the above three patents include structural features adapting it for a different mode of operation.
The following U.S. patents should also be considered for the purpose of putting the present invention into proper perspective with the prior art: U.S. Pat. No. 103,687, granted May 21, 1870 to Henry Thompson; U.S. Pat. No. 653,021, granted Jul. 3, 1900 to Charles S. Hamilton; U.S. Pat. No. 2,203,433, granted Jun. 4, 1940 to Nicolas U. Gundian; U.S. Pat. No. 2,313,802, granted Mar. 16, 1943 to Jonan F. Carlsen; U.S. Pat. No. 2,347,718, granted May 2, 1944 to Matson C. Terry; U.S. Pat. No. 2,432,125, granted Dec. 9, 1947 to Albert A. Schlaak; U.S. Pat. No. 2,432,342, granted Dec. 9, 1947 to Albert F. Shaner; U.S. Pat. No. 2,616,203, granted Nov. 4, 1952 to Joseph B. Sarakas; U.S. Pat. No. 2,633,333, granted Mar. 31, 1953 to Lynn W. Storm; U.S. Pat. No. 3,167,346, granted Jan. 26, 1965 to Marvin O. Miller; U.S. Pat. No. 3,193,318, granted Jul. 6, 1965 to William S. Guerrant, Jr.; and U.S. Pat. No. 3,653,101, granted Apr. 4, 1972 to Henry C. Mayo.